#
#
# rename "tests/commit_using__MTN_log/commit_log.lua"
#     to "tests/commit_using__MTN_log/commit_cancelled.lua"
# 
# rename "tests/commit_using__MTN_log/commit_log_modified_return.lua"
#     to "tests/commit_using__MTN_log/commit_confirmed.lua"
# 
# patch "cmd_ws_commit.cc"
#  from [3c83413e2d5067cf6ac9e79d8849191a5975f948]
#    to [e3eed43a97da68628c4fabc80ced9ea3327871f8]
# 
# patch "tests/changelog_editor/__driver__.lua"
#  from [56b86ffc51a0bf5a60f2b10e578bdd631df76796]
#    to [96e979a9afb3cdab37abc18f09b32044d8f5a4ab]
# 
# patch "tests/commit_using__MTN_log/__driver__.lua"
#  from [0766c36af8bc95807f4a2dd2b752e0e97aadb38a]
#    to [64507df85499593c9de2e854a3add3b4d6683c47]
# 
# patch "tests/commit_using__MTN_log/commit_cancelled.lua"
#  from [e1b07045d69de57d75e5b73df41124c2c94b315d]
#    to [1b64ffe9a275897fe60c629350ac44b5bb3afc62]
# 
# patch "work.cc"
#  from [28266a7fbb698d94c998047e52842b220b37756d]
#    to [7e3829c75634ee5bbf555209dfa152d0bd88138c]
# 
# patch "work.hh"
#  from [021031510460f3cdc3762460937d94b575f04154]
#    to [3f94623eb296347caca9ed341f0bee2ef63481be]
#
============================================================
--- cmd_ws_commit.cc	3c83413e2d5067cf6ac9e79d8849191a5975f948
+++ cmd_ws_commit.cc	e3eed43a97da68628c4fabc80ced9ea3327871f8
@@ -133,6 +133,14 @@ get_log_message_interactively(lua_hooks 
                               set<branch_name> const & old_branches,
                               string const & date_fmt, utf8 & log_message)
 {
+  utf8 backup;
+  work.load_commit_text(backup);
+
+  E(backup().empty(), origin::user,
+    F("A backup from a previously failed commit exists in _MTN/commit.\n"
+      "This file must be removed before commit will proceed.\n"
+      "You may recover the previous message from this file if necessary."));
+
   utf8 instructions(
     _("Enter a description of this change following the Changelog line below.\n"
       "The values of Author, Date and Branch may be modified as required.\n"
@@ -189,7 +197,8 @@ get_log_message_interactively(lua_hooks 
 
   system_to_utf8(output_message, full_message);
 
-  // FIXME: save the full message in _MTN/changelog so its not lost
+  // save the message in _MTN/commit so its not lost if something fails below
+  work.save_commit_text(full_message);
 
   message_reader message(full_message());
 
@@ -205,8 +214,13 @@ get_log_message_interactively(lua_hooks 
   E(message.read(instructions()), origin::user,
     F("Commit failed. Instructions not found."));
 
-  E(message.read(cancel()), origin::user,
-    F("Commit cancelled."));
+  if (!message.read(cancel()))
+    {
+      // clear the backup file if the commit was explicitly cancelled
+      work.clear_commit_text();
+      E(message.read(cancel()), origin::user,
+        F("Commit cancelled."));
+    }
 
   utf8 const AUTHOR(trim_right(_("Author: ")).c_str());
   utf8 const DATE(trim_right(_("Date: ")).c_str());
@@ -288,6 +302,9 @@ get_log_message_interactively(lua_hooks 
   string content = trim(message.content()) + '\n';
 
   log_message = utf8(content, origin::user);
+
+  // remove the backup file now that all values have been extracted
+  work.clear_commit_text();
 }
 
 CMD(revert, "revert", "", CMD_REF(workspace), N_("[PATH]..."),
============================================================
--- tests/changelog_editor/__driver__.lua	56b86ffc51a0bf5a60f2b10e578bdd631df76796
+++ tests/changelog_editor/__driver__.lua	96e979a9afb3cdab37abc18f09b32044d8f5a4ab
@@ -19,104 +19,161 @@ check(qgrep("date format", "stderr"))
 
 check(mtn("commit", "--date-format", "%F"), 1, false, true)
 check(qgrep("date format", "stderr"))
+check(not exists("_MTN/commit"))
 
 -- commit fails with empty message
 
 writefile("_MTN/log", "empty message")
 check(mtn("commit", "--rcfile=changelog.lua"), 1, false, true)
 check(qgrep("empty log message", "stderr"))
+check(not exists("_MTN/commit"))
 
 -- commit fails with modified/missing instructions
 
 writefile("_MTN/log", "missing instructions")
 check(mtn("commit", "--rcfile=changelog.lua"), 1, false, true)
 check(qgrep("Instructions not found", "stderr"))
+check(exists("_MTN/commit"))
+check(fsize("_MTN/commit") > 0)
+id1=sha1("_MTN/commit")
 
+-- commit fails if _MTN/commit exists from previously failed commit
+check(mtn("commit"), 1, false, true)
+check(qgrep("previously failed commit", "stderr"))
+check(exists("_MTN/commit"))
+check(fsize("_MTN/commit") > 0)
+id2=sha1("_MTN/commit")
+check(id1 == id2)
+remove("_MTN/commit")
+
 -- commit can be cancelled
 
 writefile("_MTN/log", "cancel")
 check(mtn("commit", "--rcfile=changelog.lua"), 1, false, true)
 check(qgrep("Commit cancelled.", "stderr"))
+check(not exists("_MTN/commit"))
 
 -- commit fails with modified/missing separator, Revision: or Parent: lines
 
 writefile("_MTN/log", "missing separator")
 check(mtn("commit", "--rcfile=changelog.lua"), 1, false, true)
 check(qgrep("Revision/Parent header not found", "stderr"))
+check(exists("_MTN/commit"))
+check(fsize("_MTN/commit") > 0)
+remove("_MTN/commit")
 
 writefile("_MTN/log", "missing revision")
 check(mtn("commit", "--rcfile=changelog.lua"), 1, false, true)
 check(qgrep("Revision/Parent header not found", "stderr"))
+check(exists("_MTN/commit"))
+check(fsize("_MTN/commit") > 0)
+remove("_MTN/commit")
 
 writefile("_MTN/log", "missing parent")
 check(mtn("commit", "--rcfile=changelog.lua"), 1, false, true)
 check(qgrep("Revision/Parent header not found", "stderr"))
+check(exists("_MTN/commit"))
+check(fsize("_MTN/commit") > 0)
+remove("_MTN/commit")
 
 -- commit fails with modified/missing Author: line
 
 writefile("_MTN/log", "missing author")
 check(mtn("commit", "--rcfile=changelog.lua"), 1, false, true)
 check(qgrep("Author header not found", "stderr"))
+check(exists("_MTN/commit"))
+check(fsize("_MTN/commit") > 0)
+remove("_MTN/commit")
 
 -- commit fails with empty Author: line
 
 writefile("_MTN/log", "empty author")
 check(mtn("commit", "--rcfile=changelog.lua"), 1, false, true)
 check(qgrep("Author value empty", "stderr"))
+check(exists("_MTN/commit"))
+check(fsize("_MTN/commit") > 0)
+remove("_MTN/commit")
 
 -- commit fails with modified/missing Date: line
 
 writefile("_MTN/log", "missing date")
 check(mtn("commit", "--rcfile=changelog.lua"), 1, false, true)
 check(qgrep("Date header not found", "stderr"))
+check(exists("_MTN/commit"))
+check(fsize("_MTN/commit") > 0)
+remove("_MTN/commit")
 
 -- commit fails with empty Date: line
 
 writefile("_MTN/log", "empty date")
 check(mtn("commit", "--rcfile=changelog.lua"), 1, false, true)
 check(qgrep("Date value empty", "stderr"))
+check(exists("_MTN/commit"))
+check(fsize("_MTN/commit") > 0)
+remove("_MTN/commit")
 
 -- commit fails with modified/missing Branch: line
 
 writefile("_MTN/log", "missing branch")
 check(mtn("commit", "--rcfile=changelog.lua"), 1, false, true)
 check(qgrep("Branch header not found", "stderr"))
+check(exists("_MTN/commit"))
+check(fsize("_MTN/commit") > 0)
+remove("_MTN/commit")
 
 -- commit fails with empty Branch: line
 
 writefile("_MTN/log", "empty branch")
 check(mtn("commit", "--rcfile=changelog.lua"), 1, false, true)
 check(qgrep("Branch value empty", "stderr"))
+check(exists("_MTN/commit"))
+check(fsize("_MTN/commit") > 0)
+remove("_MTN/commit")
 
 -- commit fails with modified/missing blank line before Changelog section
 
 writefile("_MTN/log", "missing blank line")
 check(mtn("commit", "--rcfile=changelog.lua"), 1, false, true)
 check(qgrep("Changelog header not found", "stderr"))
+check(exists("_MTN/commit"))
+check(fsize("_MTN/commit") > 0)
+remove("_MTN/commit")
 
 -- commit fails with modified/missing Changelog section
 
 writefile("_MTN/log", "missing changelog")
 check(mtn("commit", "--rcfile=changelog.lua"), 1, false, true)
 check(qgrep("Changelog header not found", "stderr"))
+check(exists("_MTN/commit"))
+check(fsize("_MTN/commit") > 0)
+remove("_MTN/commit")
 
 -- commit fails with missing Change summary section
 
 writefile("_MTN/log", "missing summary")
 check(mtn("commit", "--rcfile=changelog.lua"), 1, false, true)
 check(qgrep("Change summary not found", "stderr"))
+check(exists("_MTN/commit"))
+check(fsize("_MTN/commit") > 0)
+remove("_MTN/commit")
 
 -- commit fails with duplicated Change summary section
 
 writefile("_MTN/log", "duplicated summary")
 check(mtn("commit", "--rcfile=changelog.lua"), 1, false, true)
 check(qgrep("Text following Change summary", "stderr"))
+check(exists("_MTN/commit"))
+check(fsize("_MTN/commit") > 0)
+remove("_MTN/commit")
 
 -- commit fails with new text after Change summary section
 
 writefile("_MTN/log", "trailing text")
 check(mtn("commit", "--rcfile=changelog.lua"), 1, false, true)
 check(qgrep("Text following Change summary", "stderr"))
+check(exists("_MTN/commit"))
+check(fsize("_MTN/commit") > 0)
+remove("_MTN/commit")
 
 
 -- commits that succeed
@@ -131,6 +188,7 @@ check(qgrep("Branch:   left", "stdout"))
 check(qgrep("Date:     2010-01-01T01:01:01", "stdout"))
 check(qgrep("Author:   bobo", "stdout"))
 check(qgrep("Branch:   left", "stdout"))
+check(not exists("_MTN/commit"))
 
 -- test changed --date, --author and --branch options 
 
@@ -141,6 +199,7 @@ check(not qgrep("Branch:   left", "stdou
 check(not qgrep("Date:     2010-01-01T01:01:01", "stdout"))
 check(not qgrep("Author:   bobo", "stdout"))
 check(not qgrep("Branch:   left", "stdout"))
+check(not exists("_MTN/commit"))
 
 -- test unchanged date gets updated to reflect current time
 
@@ -152,6 +211,7 @@ check(old ~= new)
 old = string.match(log, "Old: ([^\n]*)")
 new = string.match(log, "Date: ([^\n]*)")
 check(old ~= new)
+check(not exists("_MTN/commit"))
 
 -- test changed date does not get updated
 
@@ -160,15 +220,18 @@ check(qgrep("Date:     2010-01-01T01:01:
 check(mtn("commit", "--rcfile=changelog.lua"), 0, false, false)
 check(mtn("log", "--last", "1", "--no-graph"), 0, true, false)
 check(qgrep("Date:     2010-01-01T01:01:01", "stdout"))
+check(not exists("_MTN/commit"))
 
 -- message on same line as Changelog: header
 
 writefile("a", "a4")
 writefile("_MTN/log", "changelog line")
 check(mtn("commit", "--rcfile=changelog.lua"), 0, false, false)
+check(not exists("_MTN/commit"))
 
 -- message filling entire Changelog section (no leading/trailing blank lines)
 
 writefile("a", "a5")
 writefile("_MTN/log", "full changelog")
 check(mtn("commit", "--rcfile=changelog.lua"), 0, false, false)
+check(not exists("_MTN/commit"))
============================================================
--- tests/commit_using__MTN_log/__driver__.lua	0766c36af8bc95807f4a2dd2b752e0e97aadb38a
+++ tests/commit_using__MTN_log/__driver__.lua	64507df85499593c9de2e854a3add3b4d6683c47
@@ -1,25 +1,25 @@ mtn_setup()
 
 mtn_setup()
 
-check(get("commit_log.lua"))
-check(get("commit_log_modified_return.lua"))
+check(get("commit_cancelled.lua"))
+check(get("commit_confirmed.lua"))
 
 writefile("_MTN/log", "Log Entry")
 writefile("input.txt", "version 0 of the file")
 
 check(mtn("add", "input.txt"), 0, false, false)
 
---this should now fail, given that the log file has content and we don't
---remove the 'magic' line
---check(mtn("--branch=testbranch", "--rcfile=commit_log.lua", "commit"), 1, false, true)
---check(qgrep('magic line; commit cancelled', "stderr"))
+-- this should now fail, given that the log file has content and the cancel line
+-- has been removed
+check(mtn("--branch=testbranch", "--rcfile=commit_cancelled.lua", "commit"), 1, false, true)
+check(qgrep('Commit cancelled.', "stderr"))
 
---check(exists("_MTN/log"))
---check(fsize("_MTN/log") > 0)
+check(exists("_MTN/log"))
+check(fsize("_MTN/log") > 0)
 
---this should pass, as the lua hook now returns a string that doesn't contain
---the 'magic' line
-check(mtn("--branch=testbranch", "--rcfile=commit_log_modified_return.lua", "commit"), 0, false, false)
+-- this should pass, as the lua hook now returns a string that still includes the
+-- cancel line
+check(mtn("--branch=testbranch", "--rcfile=commit_confirmed.lua", "commit"), 0, false, false)
 
 tsha = base_revision()
 check(exists("_MTN/log"))
============================================================
--- tests/commit_using__MTN_log/commit_log.lua	e1b07045d69de57d75e5b73df41124c2c94b315d
+++ tests/commit_using__MTN_log/commit_cancelled.lua	1b64ffe9a275897fe60c629350ac44b5bb3afc62
@@ -1,3 +1,3 @@ function edit_comment(user_log_file)
 function edit_comment(user_log_file)
-  return user_log_file
+   return string.gsub(user_log_file, "... REMOVE THIS LINE TO CANCEL THE COMMIT ...\n", "")
 end
============================================================
--- work.cc	28266a7fbb698d94c998047e52842b220b37756d
+++ work.cc	7e3829c75634ee5bbf555209dfa152d0bd88138c
@@ -53,6 +53,7 @@ static char const user_log_file_name[] =
 static char const local_dump_file_name[] = "debug";
 static char const options_file_name[] = "options";
 static char const user_log_file_name[] = "log";
+static char const commit_file_name[] = "commit";
 static char const revision_file_name[] = "revision";
 static char const update_file_name[] = "update";
 static char const bisect_file_name[] = "bisect";
@@ -93,6 +94,13 @@ static void
 }
 
 static void
+get_commit_path(bookkeeping_path & commit_path)
+{
+  commit_path = bookkeeping_root / commit_file_name;
+  L(FL("commit path is %s") % commit_path);
+}
+
+static void
 get_update_path(bookkeeping_path & update_path)
 {
   update_path = bookkeeping_root / update_file_name;
@@ -414,6 +422,41 @@ workspace::has_contents_user_log()
   return user_log_message().length() > 0;
 }
 
+// commit buffer backup file
+
+void
+workspace::load_commit_text(utf8 & dat)
+{
+  bookkeeping_path commit_path;
+  get_commit_path(commit_path);
+
+  if (file_exists(commit_path))
+    {
+      data tmp;
+      read_data(commit_path, tmp);
+      system_to_utf8(typecast_vocab<external>(tmp), dat);
+    }
+}
+
+void
+workspace::save_commit_text(utf8 const & dat)
+{
+  bookkeeping_path commit_path;
+  get_commit_path(commit_path);
+
+  external tmp;
+  utf8_to_system_best_effort(dat, tmp);
+  write_data(commit_path, typecast_vocab<data>(tmp));
+}
+
+void
+workspace::clear_commit_text()
+{
+  bookkeeping_path commit_path;
+  get_commit_path(commit_path);
+  delete_file(commit_path);
+}
+
 // _MTN/options handling.
 
 static void
============================================================
--- work.hh	021031510460f3cdc3762460937d94b575f04154
+++ work.hh	3f94623eb296347caca9ed341f0bee2ef63481be
@@ -226,6 +226,16 @@ public:
   void blank_user_log();
   bool has_contents_user_log();
 
+  // The full commit text from the edit_comment lua hook is saved before
+  // attempting to extract the various Author: Date: Branch: and Changelog:
+  // values from it in case these values don't appear where they are
+  // expected. Once all the values have been extracted the backup file is
+  // removed.
+
+  void load_commit_text(utf8 & dat);
+  void save_commit_text(utf8 const & dat);
+  void clear_commit_text();
+
   // the "options map" is another administrative file, stored in
   // _MTN/options. it keeps a list of name/value pairs which are considered
   // "persistent options", associated with a particular workspace and